DESCRIPTION (Adapted from the Applicant's Description): Human beings are able to become skilled at most complex tasks (e.g., driving) because they learn to automatize portions of the task. Despite the importance of automaticity in skill development. few studies have systematically investigated automatic process development in brain injured populations. Search tasks have been used in the laboratory to study the development of automatic processes. The proposed study will use a visually-based search task to examine skill acquisition and automatic process development in a severe closed-head injured (CHI) population. Because the automatization of task components is integral to developing skilled performances, a theoretical understanding of automatic process development after severe CHI should have important implications for remediation procedures. Across several sessions of training, CHI participants and matched controls will complete a semantic category visual search task in consistent mapping (CM) and varied mapping (VM) training situations. The investigators have shown that the CM training condition results in dramatic performance improvements and the development of an automatic attention response (AAR). VM training, on the other hand, results in little performance improvement and the continued reliance on attention-demanding or controlled processes. By comparing performances in the CM and VM conditions, the investigators propose to be able to evaluate the rate and acquisition of skilled visual search performance following a severe CHI. Transfer conditions will be used to test for general, task-related learning and for the development of an AAR, independent of general performance improvement. These data are expected to provide initial evidence for the ability of severe CHI participants to acquire general, task-related skills and develop an AAR in a visual search situation. Further studies can then examine, for example, transfer of automatized task components to more complex tasks, and ability to modify previously learned and automatized processes (i.e., "old habits").